Various methods of decorticating flax straw, that is, separating the woody shive material from the flax plant fibers, have been proposed. Apart from retting and chemical treatment processes, most systems for mechanically working flax straw rely on some sort of scutching or a beating or flailing action as the primary mechanism to break up the woody material and dislodge the same from associated fibers. Examples of machines utilizing scutching or beating action in removing shive are disclosed in U.S. Pat. Nos. 2,418,694 and 2,741,894.
The problem with beating flax straw to break loose the shive material is that the beating action can also damage or break the fibers and thereby shorten the fibers separated from the shive. In many applications for these fibers, long fibers can be necessary for strength purposes such as in papermaking, preparation of fiberboard-types of materials, production of textiles, and reinforcing other fibers, plastic or composite material, and thus the shorter fibers produced by prior methods of decortication are undesirable. In addition to longer fibers, it is also economically desirable to be able to process high rates of flax straw through decorticating machines with relatively low power requirements.